Can you think of any three-dimensional shape that comprises of exactly two surfaces?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

Look at the picture and find out which square is not linked with any of the other squares.

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

I have an eye but still cannot see.

Who am I?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

John walks into the daily grocery shop and steals a $100 bill from the shop. An hour later John returns to the shop and buys some daily products for $40. John pays the owner the $100 bill and therefore the owner returns him $60.

How much money did the owner lose?